New construction home - HVAC in attic?!

We install a whole home ventilation system through an HRV

 

https://youtu.be/F7D4Q3mjgdQ

 

Would that be using the PVC pipes going to the furnace that pull in air? Or another system added to what's already there?

 

So this particular house build doesn't seem to show any ventilation system that you can tell? That's what I've been trying to figure out. If not, how hard would it be to incorporate into the HVAC system? or should I maybe install a passive venting system?

 

Additional system

 

Okay thanks! Do you know how difficult/expensive that would be on a new build?

 

New install is usually not too bad , pricing would need to be done locally to you as it is site specific

 

Okay. What should I ask the HVAC guy when I talk to him? How to add in a fresh air return to the HVAC system? I just don't want to sound like an idiot lol

 

Does this installation have flow dampers in the duct work so you can control the amount of air...

 

Thought I saw where this was going on the 1st floor my bad!

 

I'm not sure about this but the blower motor is a variable speed system

 

This is used to balance the flow of air so you can push more cold air to the 3 rd floor.

Do you have returns on each floor?

 

No, there's only one return at the top floor by the stairs. This puts it close to the HVAC. It is a 20x30

 

Well that sucks when we had our TH built I had a return put on each floor and put the supply vents in the floors and or walls in closets and the bathroom. The air handler is inside the building envelope and the only duct work in the attic now is a 10 inch return. They did have the supply vents in the ceilings on the 3rd floor. Having the extra stuff done cost me about $1K ......

I can maintain temps on each floor within 1.6 degrees plus or minus set point temp.....

 

I did mention adding returns to each floor but I'm not sure how much "room" there is to run duct work to add them or where the returns would go.. that's the tricky thing

 

What about using a air makeup unit with heat exchanger?

 

Worked in eng consulting for awhile. Like others have said you cant do anything about it. Vents are required by code and yes the design is not as efficient as it could be (thus the introduction of LEED certification industry) but the losses your talking about are factored into the design and as long as your comfortable inside your home I wouldnt get too bent out of shape about it. If the system is under designed and problematic hopefully there is some course of new buyer recourse you can take.

Also have to mention all kinds of problems down the road you will have if you decide to fix that "vent problem" yourself with moisture.

 

I may just have the ductwork sprayed and call it good. Not sure yet, they're supposed to spray foam floored attics so we'll see what they end up doing.
Will have to ask about adding addtl returns, or at least maybe one on the ceiling of the bottom floor.

 

Looks like the next row of townhomes was sprayed. This is looking through to the attic of a 2BR.

 

From the first post, pic#3, I see that your attic insulation is going bad due to moister. This happens in the summer, when the air conditioning is running. A vapor barrier must be exposed to the warm side of a wall (ie, when hanging wall, the silver/paper side should always be on the inside, because water forms on the warm side and the foil/paper stops water from penetrating the insulation. Only water can destroy insulation, and it does a very good job at it.

Here, with your attic HVAC, the ductwork wrapped in insulation has the vapor barrier facing outward. This is good in the winter, but not in the summer. In the summertime, your duct sweats, it destroys the duct insulation, and it drips onto the attic insulation, destroying that too. Without any insulating value, all that mildew stained insulation has to be thrown out and replaced. To stop it going forward, I would cover the new insulation with plastic wrap, knowing that sweat will still occur, but the plastic will hold the water until it evaporates.

I completely agree with you that attic HVAC systems should be protected in an enclosed floor. All HVAC systems, btw, are 'closed systems', in that air is returned to the furnace from inside the house, then heated or cooled, and re-fed back to the house. The trend of placing HVAC in the attic started in the early/mid '90's (from what I remember in this area of the country), and it was to reduce cooling costs. However, insulated covered ductwork is always a problem unless both sides of the insulation have a vapor barrier. Also, when using AC, you must always keep an eye on the condensate drain, and be prepared to replace the pump (a small, rectangular $100 part) should it ever go out. So, it's good to keep an extra one on hand, just in case.

BTW: Pic #1 looks good.